Answer: Without a better description of the bugs, I can't offer much help. However, I know that Euonymus scale, a white-covered scale insect, is the most serious pest. A severe infestation will make the underside of the leaves and the entire stem white. Unless controlled, this pest will eventually kill the plant.
Euonymus scale is difficult to control. With light infestations, scale can be scraped off by hand and destroyed. Pruning out heavily infested branches is helpful. Avoid using insecticides unless the plant is very valuable and in serious danger from scale. Insecticides will often kill the naturally occurring enemies of scale.
Adult scales are relatively protected from insecticides by their waxy covering. Their immature forms, called crawlers, are susceptible, however. Horticultural oil (Bonide All Season Spray Oil, Ferti-lome Scalecide, Green Light Horticultural Oil Spray, or Ortho Volck Oil Spray) can be used as a dormant spray before new growth begins in the spring. It kills many adults and eggs by smothering them. Spray again when crawlers are present in the spring.
Hope this information helps.
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